Metal-spraying apparatus



.Feb. 17, 1931. w. s. RICE ET AL METAL sPnAYING APPARATUS Filed Nov. 4,1929 Patented Feb. 17, 1931 UNITED STATES PATENT oFFlcE 'WILLIAM S.RICE, OIF CHICAGO, ILLINOIS, AND CHARLES MARSHAL SAEGER, JR., 0WASHINGTON, DISTRICT 0F COLUMBIA .p

MErALsPaAYING APPARATUS Application led November 4, 1929. Serial No.404,850.

(GRANTED UNDER THE ACT OF MARCH 3, 1883, AS AMENDED APRIL 30, 1928; 3700. G. 757) This invention described herein may be manufactured and usedby or for the government for governmental purposes, without the .paymentto us of any royalty thereon.

This inventionfbroadly speaking, relates to apparatus forsprayingvmetal. More particularly it is directed to a spraying devicedesigned to meet the requirements of the method set forth in pendingapplication Serial No. 281,278, liled May 28, 1928, en-

titled Method for the production of denis heated to a temperatureapproximatingl that of the molten metal to prevent oxidation and insurecomplete disintegration of the metal by the air blast.

Another object of this invention is to provide an apparatus for sprayingmetal in which the coil traversed by the air and the electrical heatingelement employed to reduce the metal to a molten state are associated sothat the heating element not only flmctions to reduce the metal to amolten state but also serves as a heating means for the air coil.

Another .object of this invention is to effect a metal sprayingAapparatus' which may be readily manipulated-by the operator,conveniently transported and which is simple in construction andcomparatively inexpensive to produce.

With these and other objects in view this invention consists in certainnovel details of construction, combination and arrangement of parts tobe more particularly hereinafter described and claimed.

Briefly stated, this invention comprises a body portion in the nature ofa cyhndrical heat insulated container adapted to receive the metal to bereduced to a molten state, an

atomizing device including avhorizontallydisposed atomizing nozzlesupported immediately above the container and a tube extending from thenozzle into said container, an air coil encircling the container oneendof the coil communicating with the atomizing nozzle, the opposite endwith a source of -air under pressure and a suitably energized electricalheating element encircling the container, the turns of the heatingelement being interposed between those of the air coil.

Referring more particularly to the accompanying drawings in whichcorrespond-- ing parts are indicated by similar reference characters:Fig. 1 is a transverse vertical section partly in elevation of theentire apparatus and showing but a portion of the air supply tube.

Fig. 2 is a fragmentary sectionized detail illustrating the switchconstruction controlling energization of the electrical heating element.

Fig. 3 is a fragmentary sectionized detail taken on the line 3 3 of Fig.1

Fig. 4 is a fragmentary elevation with certain parts shown in dottedoutline and illustrating a modified form of construction and Fig. 5 is-afragmentary sect-ionized detail of the modification shown in Fig. 4.

Practice of the process disclosed in the hereinabove identifiedapplication involves among other steps coating. certain articles withmetal preliminary to producing the finished denture, and to accomplishthis, vari- ,l

lcharacter required in the method referred to.

To facilitate further discussion of this invention it will behereinafter considered in the order to wit: Namely the body portion ofthe apparatus, atomizer construction, means for effecting atomization,electrical heating element and its connections, operation, modification'and conclusion. i

Reference being had to Fig. 1 of the drawings it will be seen the bodyportion A comprises an elongated cylindrical vessel or chamber (1), thelatter being open at its upper and closed at its lower endconcentrically positioned in a similarly formed casing (2),

which is of the same height as vessel (l) but of greater diameter toprovide an annular space for the recept-ion of suitable insulatingmaterial The body portion A is manipulated by means of a hollow handgrip (4) which is spaced from and connected to the casing (2) by hollowextensions (5). Both the vessel (1) and casing (2) may be provided witha heat insulating material.

Coming now to the atomizer B this device comprisesa head (6), anadjustable nozzle (7), to var the character of the spray and anextension 8), said extension being formed at its outer end to receive aconnection (9) to be hereinafter referred to.

Extending downwardly from head (6) 'into the vessel (1) is a tube (10),the lower end of which terminates adjacent the bottom of the vessel asclearly shown in Fig. 1 of the drawings. With this arrangement it isevident as air under pressure passes through the head (6) of theatomizer the molten content of the vessel (1) will be drawn up throughtube (10) disintegrated and projected from the nozzle (7) in minuteparticles.

The means for effecting atomization (indicated generally by thereference characters C) embodies a coil (11) arranged in encirclingrelation with respect to vessel (1), the turns of thecoil starting atthe bottom of the vessel and terminating near the top thereof as clearlyshown in Fig. 1 of the drawings.'

The lower end of air coil (11) communicates with a nipple (12) extendingthrough casing (2) near its bottom. The outer end of said nipple (12) isconnected to a flexible tube (18) leading to a source of air underpressure, (not shown). The upper Aend of air coil (11) is attached tothe outer end of connection (9) thus interconnecting the atomizer B withthe source of air under pressure through the coil. To control the airsupply and hkewise indicate pressure, connection (9) of nozzle B may beequip ed with a ressure gauge (14) and a cut-o valve (15 Reduction ofthe metal in vessel (1) to a molten state is accomplished by means of anable conductors with a source of electrical en-y electricalheatingelementD connected by suitergy. The electrical heating element Dcomrises coil (16) which encircles vessel (1) o r the greater portion ofits length, the turns of said element being disposed intermediatel thoseof the air coil as clearly shown in Fig. 1 of the drawings. c

By arranging the heating element in this manner it serves not only toreduce the metal in vessel (1) to a molten state, but also to heat theturns of the air coil so that as the air enters the atomizing nozzle itstemperature will correspond substantially to that of the molten metal.

One terminal of the heating coil (11) is connected to a conductor (17)extending through hollow extensions (5) of hand grip (4) and outlet (18)positioned in the'lower end of said grip. The other terminal-of theheating coil (11) is connected to conductor (19) extending to oneterminal (20) of switch E, the remaining terminal (21) of said switchbeing connected to conductor (22), which passes through the outlet (18)to the exterior of the` handle.

Although switch E may be of any suitable construction in'the presentembodiment it consists of a pair of resilient contacts (23) and (24)adapted to be brought into engagement by means of a button (25) slidablymounted on hand grip Locating the switch E on the hand grip (4) enablesthe circuit of the heating element to be readily controlled duringmanipulation of the sprayer as will be readily understood withoutfurther discussion.

Having'defned the structural details oi this invention its operation isas follows: The metal to be sprayed is placed in the vessel or chamber(l) and switch E is closed to complete the circuit through the heatingelement (11). Vhen the metal has been reduced to a molten state theoperator opens valve (15) whereupon the air under pressure enters thelower end of air coil (11), passes through its several turns and issuesfrom the nozzle ofthe atomizer at high velocity. In traversing the turnsof the heating element the air is subjected to the heating action of themolten metal and also to that of the heating coil (16) in consequence ofwhich as the air enters the atomizer B, its temperature approximatesthat of the molten metal, and as a result of this feature the metal isatoniized and solidilied before oxidation can occur. Passing through thenozzle over the open end of tube (l0) the air draws the molten metal upthrough the tube, disintegrates it and projects the disintegrationthrough the nozzle (7), to quickly metallize any object exposed to thespray.

Instead of encircling the vessel (1) with the coil and heating elementas shown in Fig.

l, the coil may be positioned within said Ves-V sel (1) and the latterencircled by the heating element as shown in Figs. 4 and 5 of thedrawings.- In this construction the tube (10) extending through atomizerB projects.

noted atomizer B is supported immediately above the` open end of vessel(l) by means of a bracket F embodying a loop portion (26) which embraceshead (6) and oppositely extending legs (27'), the extremities of whichare formed with laterally spaced downwardly projecting lugs (28) adaptedto engage the upper edge or body portion A as clearly shown in Fig. 5 ofthe drawings.

1n conclusion it is to be understood that although in the foregoingcertain elements have been described as best" adapted to perform thefunctions allotted them, nevertheless it is to be understood thatvarious minor changes may be resorted to within the scope of theappended claims without departing from or sacrificing any of theprinciples of the invention.

Having described our invention, what we claim as new and wish to secureby Letters Patent is:

1. An apparatus for coating surfaces with hot molten substancescomprising a heating chamber adapted to receive the substance to bereduced to a molten state, an atomizing nozzle disposed above thechamber, an induction tube communicating with the interior of the nozzleand extending into the chamber, an air supply under pressure, atube'con'necting said air supply with the atomizing nozzle, said tubefor the greater portion of its length encircling the heating chamber, anelectrical heating coil surrounding the said chamber, the turns of theheating coil being situated between those of the air coil to heat thecontents of the heating chamber and also the air as it passes throughthel tube to the atomizing nozzle, and energizing means in connectionwith the said electrical heating coil.

2. An apparatus for coating surfaces with hot molten substancescomprising a heating chamber adapted to receive the substance to bereduced to a molten state, an atomizing nozzle, a bracket spanning theupper end of the heating chamber and horizontally supporting theatomizing nozzle above said chamber, an induction tube communicatingwith the interior of the nozzle and extending into the heating chamber,an air supply under pressure, a tube connecting the air supply with theatomizing nozzle, said tube for the greater portion of its lengthencirclingV the heat ing chamber, an electrical heating coil surroundingthe said chamber, the turns of the heating coil being situated betweenthose of the air coil to heat the contents of the heating chamberandalso the air as it passes through the tube to the atomizing nozzle, andenergizing means in connection with the said electrical heating coil.

, 3. An apparatus for coating surfaces with hot molten substancescomprising a heating chamber adapted to receive the substance to bereduced to a molten state, a casing embracing the heating chamber and inspaced relation with respect thereto to form an annular insulationspace, insulating material within said space, a bracket extending acrossthe upper extremities of the heating chamber and casing, an atomizingnozzle horizontally supported by the bracket above the upper end of saidheating chamber, an induction tube communicating with the interior ofthe nozzle and extending into the heating chamber to a position adjacentits lower end, an air supply under pressure, a tube connecting the airsupply with the atomizing nozzle, said tube at the greater portion ofits length encircling the cylindrical heating chamber, a heating coilsurrounding the heating chamber, the turns of the heating coil beingdisposed between those of the air coil to heat the contents of saidchamber, and the air as it traverses the coil to the atomizing nozzleandmeans for energizing said electrical heatin coil.

l/VILLIAM S. RICE. CHARLES M. SAEGER, JR.

